21540527473 has 2 divisors, whose sum is σ = 21540527474. Its totient is φ = 21540527472.

The previous prime is 21540527453. The next prime is 21540527497. The reversal of 21540527473 is 37472504512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15004290064 + 6536237409 = 122492^2 + 80847^2 .

It is a cyclic number.

It is not a de Polignac number, because 21540527473 - 2²¹ = 21538430321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21540527443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770263736 + 10770263737.

It is an arithmetic number, because the mean of its divisors is an integer number (10770263737).

Almost surely, 2^21540527473 is an apocalyptic number.

It is an amenable number.

21540527473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540527473 is an equidigital number, since it uses as much as digits as its factorization.

21540527473 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 235200, while the sum is 40.

The spelling of 21540527473 in words is "twenty-one billion, five hundred forty million, five hundred twenty-seven thousand, four hundred seventy-three".